[Blink>Media] Add Chrome feature for disabling autoplay unmuted in WebAPK

chrome/browser/chrome_content_browser_client.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "chrome/browser/chrome_content_browser_client.h"
 
 #include <map>
 #include <set>
 #include <utility>
 #include <vector>
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   if (base::CommandLine::ForCurrentProcess()->HasSwitch(
           switches::kEnablePotentiallyAnnoyingSecurityFeatures)) {
     web_prefs->disable_reading_from_canvas = true;
     web_prefs->strict_mixed_content_checking = true;
     web_prefs->strict_powerful_feature_restrictions = true;
   }
 
   web_prefs->data_saver_enabled = GetDataSaverEnabledPref(prefs);
 
 #if defined(OS_ANDROID)
-  content::WebContents* contents =
-      content::WebContents::FromRenderViewHost(rvh);
-  if (contents) {
-    TabAndroid* tab_android = TabAndroid::FromWebContents(contents);
-    if (tab_android) {
-      web_prefs->media_playback_gesture_whitelist_scope =
-          tab_android->GetWebappManifestScope();
+  if (base::FeatureList::IsEnabled(
+          features::kAllowAutoplayUnmutedInWebappManifestScope)) {
+    content::WebContents* contents =
+        content::WebContents::FromRenderViewHost(rvh);
+    if (contents) {
+      TabAndroid* tab_android = TabAndroid::FromWebContents(contents);
+      if (tab_android) {
+        web_prefs->media_playback_gesture_whitelist_scope =
+            tab_android->GetWebappManifestScope();
+      }
     }
   }
 #endif  // defined(OS_ANDROID)
 
   for (size_t i = 0; i < extra_parts_.size(); ++i)
     extra_parts_[i]->OverrideWebkitPrefs(rvh, web_prefs);
 }
 
 void ChromeContentBrowserClient::BrowserURLHandlerCreated(
     BrowserURLHandler* handler) {
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     RedirectNonUINonIOBrowserThreadsToTaskScheduler() {
   return variations::GetVariationParamValue(
              "BrowserScheduler", "RedirectNonUINonIOBrowserThreads") == "true";
 }
 
 // static
 void ChromeContentBrowserClient::SetDefaultQuotaSettingsForTesting(
     const storage::QuotaSettings* settings) {
   g_default_quota_settings = settings;
 }